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作 者 ：谭龙涛， 喻春明， 陈平， 王延周， 朱娟娟， 陈继康， 卢凌霄， 熊和平

期 刊 ：核农学报 2016年 30卷 2期 页码：388-395

关键词：水杨酸；干旱胁迫；苎麻；氮代谢；纤维发育；

Keywords:salicylic acid, drought stress, ramie(Boehmeria nivea L.), nitrogen metabolization, fiber development,

摘 要 ：以中苎2号为研究对象,通过设置干旱胁迫(DS)、1 mmol·L^-1水杨酸(SA)喷施+干旱胁迫(DS+SA)、1 mmol·L ^-1SA喷施+正常浇水(CK+SA)、正常浇水(CK)4个处理,研究干旱胁迫下外源SA对苎麻可溶性蛋白和可溶性糖、叶片和韧皮部相关酶活性等生理机制及其生长发育的影响。结果表明,干旱胁迫第20天时,与DS处理相比,DS+SA处理的苎麻叶片可溶性蛋白和可溶性糖含量显著增加(P<0.05),分别提高了20.02%和17.91%。外源SA能明显缓解胁迫植株的氮代谢相关酶(NR、GS、GOGAT和GDH)和纤维发育相关酶(蔗糖合成酶、IAA氧化酶和β-1,3-葡聚糖酶)活性的降低;到干旱胁迫第20天和第30天,DS+SA处理NR活性比DS处理提高了2.02倍和0.73倍,GOGAT活性提高了67.83%和22.90%,而DS+SA处理的GS活性到干旱胁迫第10天和第20天与DS处理差异显著(P<0.05)。DS处理的纤维发育相关酶到第30天下降幅度较大,3种酶活性分别只有CK的37.84%、30.71%和35.73%,而DS+SA处理能达到CK的58.23%、74.17%和60.11%。干旱导致苎麻生长缓慢,生物量与CK差异显著(P<0.05),经DS+SA处理的植株的产量指标均高于DS处理。因此,在干旱胁迫下,外源水杨酸能够明显缓解植物体内相关酶活性的降低,维持植物正常生长,增强苎麻植株对干旱胁迫的耐受性。本研究为苎麻应对干旱胁迫提供了理论依据。

Abstract:In order to explore effects on soluble protein content, soluble sugar content and enzymes activities in leaves and phloem of Zhongzhu No2 were studied under four treatments (DS, DS+SA, CK+SA and CK). The results showed that the soluble protein and soluble sugar contents under DS+SA treatment in leaves were significantly increased than DS treatment(P<0.05). The activities NR, GS, GOGAT, GDH in leaves and the activities of sucrose synthase, IAA oxidase, β-1,3-glucanase in phloem significantly decreased under drought stress. Exogenous SA in ramie was significantly increased the enzymes activities in leaves and phloem, meanwhile, NR activity of DS+SA treatment was 2.02 and 0.73 times over DS treatment, and GOGAT activity increased by 67.83% and 22.90% on the 20^th and 30^th day, respectively. GS activity was significantly different between DS+SA and DS treatments on the 10^th and 20^th (P<0.05). Three key enzymes activities involving fiber development in phloem had a significant decrease compared with CK treatment on the 30^th day, and for DS treatment, they were 37.84%, 30.71% and 35.73%, respectively, while for DS+SA treatment, they were 58.23%, 74.17% and 60.11%, respectively. The growth rate and aerial biomass of ramie were both reduced under the drought stress, but with the exogenous SA, plant height and yield were all recovered. Therefore, these results indicated SA enhanced the activities of enzymes and mitigated the effect of drought stress of ramie. This provides a theoretical basis for ramie in response to drought stress.

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